Pressure responsive electric control system employing an ion drag pump



June 8 1965 o. M. sTUETzER 3 1 PRESSURE RESPONSIVE ELECTRIC CONTROL SYSTEM EMPLOYING AN ION DRAG PUMP Filed May 31, 1961 LOAD HlGH VOLTAGE D.C. GEN.

INVENTOR. OTMAR M. STUETZER ATTORNEY United States Patent Oi.

3 188,551 PRESSURE RESPGNWE ELECTRIC CUNTROL SYSTEM EMPLYING AN IGN DRAG PUMP Otmar M. Stuetzer, Hopkins, Minn., assigner, hy inc sne assignments, to Litton Systems, Ine., Beverly Hills,

Calif., a corporation of Maryland Filed May 31, 1961, Ser. No. 113,819 6 Claims. (Ci. 322-39) This invention relates generally to electric regulators, and pertains more particularly to apparatus for regulating and/or fusing very high voltages, that is, voltages in the neighborhood of from 20,000 to 5,000,000 volts.

While devices have been employed for controlling high voltages, they have not proved generally satisfactory. For instance, safety spark gaps are frequently used but they do not have the ability to actually regulate the system or to turn'the system ott should circumstances so dictate. On the other hand, control has been effected by using a high voltage resistor to obtain a current proportional to the voltage to be controlled. However, such high voltage resistors are subject to corona losses if they are made quite thin. Furthermore, such resistors are not very constant in their action, permitting deviations that in many instances cannot be tolerated.

Accordingly, an object of the present invention is to provide an electric regulator that will satisfactorily con` trol very high voltages to the extent that they can be actually interrupted if conditions so warrant, yet in other situations operate in a fashion so as to control or regulate the magnitude voltage so that objectionably high voltages are not experienced.

Another object of the invention is to provide an electric regulator having even more general utility than that mentioned in the preceding paragraph. lnthis regard, it is an aim of the invention to control various electrical characteristics should their control be desired. For instance, it is Within the contemplation of the invention to employ a piezoelectric material which can be acted upon so as to control the frequency of a circuit. In this same general manner, the invention envisages the compressing of a gas between two capacitor plates so as to control the capacitance of a circuit due to pressural changes effected with the regulator constituting the present invention. However, the invention is believed to iind its greatest utility in the control of voltages, as outlined above. f

A further object of the invention is to provide a device of the foregoing character which is quite small and which will use very little power in its operation.

Yet another object of the invention is to provide an electric regulator that is very rugged and reliable.

Other objects Will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exempliiied in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawing:

The single gure constituting the drawing depicts schematically one form my invention may assume.

Referring now in detail to the drawing, an insulating tubular housing 10 has been depicted. At the upper end of the tubular housing 10 is a metal cap 12 having a vent at 14, although the vent is not absolutely necessary. Disposed at the lower end of the tubular housing 10 is a bellows 16. The tubular housing 10 is maintained in an elevated position by reason of a downwardly depending skirt 18, the bellows 16 being contained in the con- Patented June 8, 1965 iines of the skirt so that it is free to expand downwardly in a manner presently to be described.

Projecting radially inwardly from the metal cap 12 is an emitter electrode 20 having a rather sharp centrally located point thereon. The emitter electrode cooperates with a conical collector or catcher electrode 22 supported at the upper end of a semiconducting tube labelled 24 which is only partly or slightly electrically conductive. Whereas the outertubular housing 10 may be made of glass, it is planned that the tube 24 be of vinyl plastic or the like. essential, however.

The interior of the tubular housing 10 contains an insulating liquid such as industrial grade kerosene, transformer o-il, Freon, CC14, or a light mineral oil. It will be appreciated that the bellows 16 closes the lower end of the tubular housing 10 and thereby retains the liquid 26 within the housing 10 as well as within the bellows 16.

For energizing the electrodes 20, 22 a high voltage DC. generator labelled 28 is provided, this generator having terminals 30 and 32. For purposes of description it Will be assumed that the generator 28 is of the Van de Graaff variety, this type of generator being quite well known. The salient or main purpose of the generator 2S is to furnish power to a load 34.

However, it is possible that the voltage output from the generator 28 may exceed safe limits, and a switch mechanism denoted by the numeral 36 is employedy under the bellows 16, the switch mechanism being actuated `into open position by reason of a plunger 38. When the switch 36 is open, the load 34 is disconnected from the generator 28.

The motor for driving the generator 28 has been indicated at 40, this motor hav-ing a iield 42 and a -source of energizing power labelled 44.

inasmuch as it is one aim of the invention to regulate the voltage output from the generator 28, a rheostat 46 has been pictured. In the exemplified situation, the rheostat 46 includes a resistance 48 which is engaged by a wiper arm 50 carried on a segmental pinion 52 which is in mesh with a rack 54 mounted on the underside of the bellows 16.

At this time, it can be explained that the electrodes 20 and 22 constitute the heart of an ion drag pump. Should additional information be desired with respect to the functioning of an ion drag pump, resort can be made to an article tilted Ion Drag Pressure Generation appearing on page 984 of the July 1959 issue of the'lournal of Applied Physics (volume 30, No. 7). For the purpose of discussion at this moment, though, it will suflice to point out that the pressure that is built up between the emitter electrode 20 and the collector elecrode 22 is proportional to (U1-U2)2, where U1 is the applied voltage from the generator 2S and U2 is the voltage at which a limited space charge conduction occurs. U2 is usually quite small with respect to the applied voltage U1 and will generally lie between 1.5 and 4 kv. Due to the ions generated by the difference in voltage between the electrodes 20, 22 a pressure is built up which acts against the bellows 16 to expand same.

Thus, when a voltage increase is made across the terminals 30, 32 of the generator 23, the pressure will be greater within the tubular housing 10 and an expansion of the bellows 1.6 will take place which moves the rack 54 downwardly. Downward movement of the rack 54, however, causes rotation `of the segmental pinion 52 in a manner such as to increase the resistance provided by the rheostat 46. Such action results in a slowing down of the motor 40 and a reduction in the output voltage ofthe generator 28 owing to its reduced speed. Consequently, the voltage across the terminals 30, 32 is lowered and a concomitant lowering of the voltage across the elec- The tube 24 is not absolutelyv situation where the bellows 16 is not employed.

trodes Zd, 22 is experienced. ln this fashion, the voltage delivered to the load 3d is actually regulated and can be held within prescribed limits of variation.

.Cognizancegis taken of the fact that under someY circumstances a disconnection of the load 34 should be effected. It is the Yrole of the switch 36 to perform this task should circumstances so dictate. With the switch 36 xedly disposed beneath the bellows le, it can be seen that if sullicient expansion of the bellows 16 occurs, then the plunger 38 will be forced downwardly to open the contacts 36 and thus remove the load 34 from across the terminals 30, 32 of the generator.

While the invention has been describedin conjunction Y ingY a quantity of ionizable fluid, an emitter electrode xedly disposed at one locus within said fluid, a collector electrode fixedly disposed at a second locus within said f fluid, a relatively high'voltage supply circuit connected to said electrodes for causing said electrodes to pump said liuid and create fluid pressure in said housing anda device responsive to said fluid pressure developed in said housing by said electrodes` for controlling an electrical characteristic of said supply circuit inaccordance With said with voltage regulating and fusing operations, it will be n appreciated that the invention is susceptible to broader application.l For instance, a piezoelectiicgdevice might be located at the bottom ofthe tubular housing l@ in a In other words, the tubular housing lill might be provided with a solid. bottom on which the piezoelectric device can rest. The piezoelectric device could be used for frequency control and in certain situations for voltage control, too. Where frequency control is desired, an even simpler arrangement might be employed. In this envisaged situation, a gas pocket might be employed at the end of the tubular housing l@ where the tubular housing l@ is formed Vwith a U-shaped lower end. A gas pocket confined within the lower U-shaped configuration might lie between two capacitor plates so that the capacitance will be changed due to compression and expansion ofthe gas so contained.

As another modilication, it will be appreciated that the ybellows 16 might constitute a carbon pile regulator which is subjected to pressure from the lluid 26 due to the ionV producing action of the electrodes Ztl, 22. This proposed carbon pile regulator would then be in the'circuitry of the motor 4t) so as to control the speed of the generator 23.

As many changes could be made in the above construc-k tionand many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and Vnot in a limiting sense. t It is also to be understood that'the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed:

1. An electric regulator comprising a housing containdeveloped fluid pressure.

Z. An electric regulator in accorduance with claim ll in which said electrical characteristic is a variable'voltage and saiddevice includesra rheostat for maintaining said voltage substantially constant. l f

3. VAn electric regulator in accordanceY with claim ll in which said electrical characteristic is a variable voltage and said device includes a'switchv for opening said supply circuit upon a predetermined voltage increase.

4. An electric regulator comprising .an elongated housing containing a quantity of ionizable liquid, an emitter electrode disposed adjacent one end of said housing within said liquid, a collector electrode located near said emitter electrode within said liquid, a relatively high voltage supply circuit connected to said electrodes for rendering said electrodes effective to pump said liquid to create pressure in said housing, `and pressure sensitive means adjacent the other end of said housing responsive to said liquid pressure developed upon energizat-ion of said electrodes for controlling an electrical characteristic of said supply circuit in accordance with said developed pressure. Y

`5. An electric regulator inY accordance with claim 4 f in which said pressure sensitive means includes a flexible bellows member closing said other end of said housing.

'6.' An apparatus -for regulating `an electrical supply unitY Jwhich produces .an electrical signal, the combination with said supply unit of an ion drag pump havinga pair of electrodes connected to said supply unit for producing duid pressure in response to the -signal rfrom said supply unit, `and means responsive to the duid pressure developed by said ion drag pump for-controlling said `supply unit.

References Cited bythe Examiner UNITED vsrA'rEs. PATENTS LLOYD MCCOLLUM, Prima-ry Examiner.

' MILTON O. HIRSHFIELD, Examiner. 

1. AN ELECTRIC REGULATOR COMPRISING AN HOUSING CONTAINING A QUANTITY OF IONIZABLE FLUID, AN EMITTER ELECTRODE FIXEDLY DISPOSED AT ONE LOCUS WITHIN SAID FLUID, A COLLECTOR ELECTRODE FIXEDLY DISPOSED AT A SECOND LOCUS WITHIN SAID FLUID, A RELATIVELY HIGH VOLTAGE SUPPLY CIRCUIT CONNECTED TO SAID ELECTRODES FOR CAUSING SAID ELECTRODES TO PUMP SAID FLUID AND CREATE FLUID PRESSURE IN SAID HOUSING AND A DEVICE RESPONSIVE TO SAID FLUID PRESSURE DEVELOPED IN SAID HOUSING 